1. Field of the Invention
The present invention relates to an apparatus that inspects a panel of a liquid crystal display (LCD.
2. Discussion of the Related Art
Generally, LCD inspection apparatuses are adapted to easily inspect, with the naked eye, whether or not an LCD panel is defective.
FIGS. 1 and 2 illustrate a conventional LCD inspection apparatus. As shown in FIGS. 1 and 2, the conventional LCD inspection apparatus includes a body 1, an inspection stage 2 which is arranged at one side of the body 1, to perform an inspection of an LCD panel 10, to be inspected, and a loading/unloading stage 7 which is arranged at the other side of the body 1, to load the LCD panel 10, to be inspected, in the inspection stage 2, and to unload the inspected LCD panel 10 from the inspection stage 2.
As seen in FIG. 2, the LCD inspection apparatus also includes a carrier 9 which is mounted to the body 1 such that the carrier 9 is laterally movable. The carrier transfers the LCD panel 10 from the loading/unloading stage 7 to the inspection stage 2, or from the inspection stage 2 to the loading/unloading stage 7.
The inspection stage 2 includes probe units 3, and a worktable 4 which brings the LCD panel 10 into contact with the probe units 3. The worktable 4 also provides light. The worktable 4 includes a polarizing plate 4a and a backlight 4b. A moving stage 5 is arranged at the rear of the worktable 4, to move the worktable 4 such that the worktable 4 is connected to the probe units 3 in a state of being aligned with the probe units 3.
A sub table 8 is mounted to the loading/unloading stage 7. The sub table 8 functions to incline the LCD panel 10 transferred from a loader (not shown) of the loading/unloading stage 7 by a predetermined angle (for example, 60°).
A microscope 6 is mounted to the body 1 in front of the inspection stage 2 such that the microscope 6 is movable in vertical and lateral directions. When it is determined, in a macroscopic inspection operation, that the LCD panel 10 has defects, the operator can more precisely identify the defects of the LCD panel 10, using the microscope 6.
An inspection procedure carried out in the above-mentioned conventional LCD inspection apparatus will now be described.
An LCD panel 10 to be inspected is transferred from the loader (not shown) of the loading/unloading stage 7 to the sub table 8 which, in turn, transfers the LCD panel 10 to the carrier 9 while being inclined by a predetermined angle. Subsequently, the carrier 9 feeds the LCD panel 10 to the inspection stage 2. When the LCD panel 10 is placed in the inspection stage 2, the worktable 4 is moved toward the LCD panel 10 in accordance with operation of the moving stage 5. Thereafter, the worktable 4 vacuum-chucks the LCD panel 10 such that the LCD panel 10 is maintained in a fixed state, and then connects pads (not shown) of the fixed LCD panel 10 to lead pins (not shown) of the probe units 3, respectively.
When electrical connection is achieved between the LCD panel 10 and the probe units 3, as mentioned above, a predetermined image signal from a pattern generator is input to the LCD panel 10 via the probe units 3. The pattern generator, which is an external image signal input unit, sequentially provides various image patterns. When the LCD panel 10 is illuminated by the backlight 4b, such various image patterns are sequentially displayed on the LCD panel 10. Accordingly, the operator can determine whether or not the LCD panel 10 is defective, through the displayed patterns.
However, the above-mentioned conventional LCD inspection apparatus has various problems. When an inspection is to be performed of the LCD panel 10 using the conventional LCD inspection apparatus, the operator first performs a macroscopic inspection with the naked eye, to detect defects present on the LCD panel. However, when fine dust D is attached to the surfaces of upper and lower substrates 11 of the LCD panel 10, as shown in FIG. 3, it is very difficult for the operator to distinguish point defects of pixels from the fine dust D.
Thus, even in the case of non-defective products, the LCD panel may be determined to be defective. For this reason, there are problems of a degradation in yield and loss of manufacturing costs.
In addition, the time taken for one operator to complete a macroscopic inspection of the LCD panel 10 is increased when the LCD panel has an increased size.
The conventional LCD inspection apparatus also has a problem in that detection of defect information of the LCD panel 10 may be omitted because the operator cannot easily identify the defect information.